This invention relates to solvents for alternating aliphatic polyketones and their use in the preparation of polyketone solutions.
Polymers of carbon monoxide and ethylenically unsaturated hydrocarbons commonly referred to simply as aliphatic polyketones have been known for some time. High molecular weight alternating aliphatic polyketones (hereafter, "polyketones") are of considerable interest because they exhibit a good overall set of physical and chemical properties. This class of polymers is disclosed in numerous U.S. patents assigned to Shell Oil Company exemplified by U.S. Pat. Nos. 4,880,903 and 4,880,904 which are incorporated herein by reference. These polymers are relatively high molecular weight materials having a breadth of useful properties giving them established utility as premium thermoplastics in the production of shaped articles such as gears, bearings, pipes, hose, connectors, fiber and parts for the automotive industry. The polymers display high strength, rigidity, and toughness among other favorable properties which they retain under a wide range of conditions such as temperature, moisture, and the presence of harsh chemical agents. For example, thinly molded parts comprised of polyketones have shown excellent property retention in concentrated acidic solutions.
To date, few reagents have been found useful as solvents for polyketones. The few reagents which can be used in this regard are expensive or can pose safe handling difficulties. Hexafluoroispropanol (HFIPA) and m-cresol are examples of such solvents. To date, HFIPA has been the only solvent known to be capable of completely dissolving polyketones at ambient temperatures (23.degree. C.).
It would be useful to have a number of solvents for polyketones so that polymer solutions could be prepared. This could make available a number of technologies not generally associated with such polymers. Solution spinning of polyketone fibers, for example, would be greatly advanced by such a development.